The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of royalties thereon or therefor.
(1) Field of the Invention
The present invention relates to a fixture to be used in leak tests. The fixture may be utilized to perform pressure/vacuum testing of devices, such as missile tube penetrators, having an open end and a closed end.
(2) Description of the Prior Art
A variety of devices are known in the art to be used during pressure/leak testing. For example, U.S. Pat. No. 3,045,475 to Pfundt illustrates a pressure test clamp developed for the pressurizing/testing of round cable assemblies. The clamping pressure and effectiveness in sealing of the Pfundt clamp are contingent upon the action of a spring located in the handle.
U.S. Pat. No. 3,390,569 to McMeekin illustrates a finish inspection apparatus for glass containers. This apparatus does not physically fasten to the vessel to be tested. Rather, it relies upon a constant vacuum source to remain mated.
U.S. Pat. No. 4,809,751 to McKenzie illustrates a pressure test cap. The cap uses an expandable collect to facilitate tightening/sealing against interior and exterior walls of a shaped duct. This feature renders the McKenzie cap ineffective in testing a collar having external threads.
U.S. Pat. No. 5,548,992 to Hallet et al. illustrates a device intended for use in leak detection where a trace gas is installed into the container to be tested, a part of which is then removed to allow use of a mass spectrometer. The actual leak testing is accomplished by use of the mass spectrometer.
U.S. Pat. No. 5,576,479 to Emmitte, Jr. shows a device designed for the testing of a pressure chamber where both ends of the chamber are open and accessible.
U.S. Pat. No. 5,777,209 to Tien relates to a leakage detection apparatus. The Tien apparatus includes a pressure chamber specifically sized to fit semiconductor components. The apparatus is made to be used in conjunction with a trace gas and leak detector.
These devices are not well suited to perform pressure/vacuum testing and/or to verify that there are no defects or damage on the face of the device being tested which can prevent proper sealing during the normal use of the device being tested.
Accordingly, it is an object of the present invention to provide an improved fixture for conducting pressure/leak testing.
It is a further object of the present invention to provide a fixture as above which can detect defects or damage on the face of the device being tested.
The foregoing objects are attained by the fixture of the present invention.
In accordance with the present invention, a fixture for conducting pressure/leak testing of a device comprises a shell having a main body and a coupling ring surrounding the main body. The coupling ring is provided with threads for engaging an external thread connection on the device being tested and thereby secure the fixture to the device. The threaded coupling ring has the advantage of permitting easy installation and removal of the fixture.
The fixture further comprises a back plate welded to the main body and an adapter to be connected to a pressure or vacuum source. The fixture further comprises an optional insulator, which insulator has at least one through hole for allowing pressurized air or for a vacuum to be applied to the device being tested.
Other details of the fixture of the present invention, as well as other objects and advantages attendant thereto, are set forth in the following detailed description and the accompanying drawings wherein like reference numerals depict like elements.